XIST and MUC1-C form an auto-regulatory pathway in driving cancer progression

The long non-coding RNA X-inactive specific transcript (lncRNA XIST) and MUC1 gene are dysregulated in chronic inflammation and cancer; however, there is no known interaction of their functions. The present studies demonstrate that MUC1-C regulates XIST lncRNA levels by suppressing the RBM15/B, WTAP and METTL3/14 components of the m6A methylation complex that associate with XIST A repeats. MUC1-C also suppresses the YTHDF2-CNOT1 deadenylase complex that recognizes m6A sites and contributes to XIST decay with increases in XIST stability and expression. In support of an auto-regulatory pathway, we show that XIST regulates MUC1-C expression by promoting NF-κB-mediated activation of the MUC1 gene. Of significance, MUC1-C and XIST regulate common genes associated with inflammation and stemness, including (i) miR-21 which is upregulated across pan-cancers, and (ii) TDP-43 which associates with the XIST E repeats. Our results further demonstrate that the MUC1-C/XIST pathway (i) is regulated by TDP-43, (ii) drives stemness-associated genes, and (iii) is necessary for self-renewal capacity. These findings indicate that the MUC1-C/XIST auto-regulatory axis is of importance in cancer progression.

IDENTIFICATION OF MUC1-C AS A TARGET FOR SUPPRESSING PROGRESSION OF HEAD AND NECK SQUAMOUS CELL CARCINOMAS

The MUC1-C protein is aberrantly expressed in adenocarcinomas of epithelial barrier tissues and contributes to their progression. Less is known about involvement of MUC1-C in the pathogenesis of squamous cell carcinomas (SCCs). Here, we report that the MUC1 gene is upregulated in advanced head and neck SCCs (HNSCCs). Studies of HNSCC cell lines demonstrate that the MUC1-C subunit regulates expression of (i) RIG-I and MDA5 pattern recognition receptors, (ii) STAT1 and interferon (IFN) regulatory factors, and (iii) downstream IFN-stimulated genes (ISGs). MUC1-C integrates chronic activation of the STAT1 inflammatory pathway with induction of the ∆Np63 and SOX2 genes that are aberrantly expressed in HNSCCs. In extending those dependencies, we demonstrate that MUC1-C is necessary for NOTCH3 expression, self-renewal capacity and tumorigenicity. The findings that MUC1 associates with ∆Np63, SOX2 and NOTCH3 expression by scRNA-seq analysis further indicate that MUC1-C drives the HNSCC stem cell state and is a target for suppressing HNSCC progression.

MUC1-C Is a Common Driver of Acquired Osimertinib Resistance in NSCLC

INTRODUCTION

Osimertinib is an irreversible EGFR tyrosine kinase inhibitor approved for the first-line treatment of patients with metastatic NSCLC harboring EGFR exon 19 deletions or L858R mutations. Patients treated with osimertinib invariably develop acquired resistance by mechanisms involving additional EGFR mutations, MET amplification, and other pathways. There is no known involvement of the oncogenic MUC1-C protein in acquired osimertinib resistance.

METHODS

H1975/EGFR (L858R/T790M) and patient-derived NSCLC cells with acquired osimertinib resistance were investigated for MUC1-C dependence in studies of EGFR pathway activation, clonogenicity, and self-renewal capacity.

RESULTS

We reveal that MUC1-C is up-regulated in H1975 osimertinib drug-tolerant persister cells and is necessary for activation of the EGFR pathway. H1975 cells selected for stable osimertinib resistance (H1975-OR) and MGH700-2D cells isolated from a patient with acquired osimertinib resistance are found to be dependent on MUC1-C for induction of (1) phospho (p)-EGFR, p-ERK, and p-AKT, (2) EMT, and (3) the resistant phenotype. We report that MUC1-C is also required for p-EGFR, p-ERK, and p-AKT activation and self-renewal capacity in acquired osimertinib-resistant (1) MET-amplified MGH170-1D #2 cells and (2) MGH121 Res#2/EGFR (T790M/C797S) cells. Importantly, targeting MUC1-C in these diverse models reverses osimertinib resistance. In support of these results, high MUC1 mRNA and MUC1-C protein expression is associated with a poor prognosis for patients with EGFR-mutant NSCLCs.

CONCLUSIONS

Our findings reveal that MUC1-C is a common effector of osimertinib resistance and is a potential target for the treatment of osimertinib-resistant NSCLCs.

MUC1-C is a target of salinomycin in inducing ferroptosis of cancer stem cells

The oncogenic MUC1-C transmembrane protein is a critical effector of the cancer stem cell (CSC) state. Addiction to MUC1-C for self-renewal in the progression of human cancers has emphasized the need for development of anti-MUC1-C agents. However, there are presently no approved small molecules for targeting MUC1-C-dependent CSCs. In screening for small molecules, we identified salinomycin (SAL), an inducer of ferroptosis, as a potent inhibitor of MUC1-C signaling. We demonstrate that SAL suppresses MUC1-C expression by disrupting a NF-κB/MUC1-C auto-inductive circuit that is necessary for ferroptosis resistance. Our results show that SAL-induced MUC1-C suppression downregulates a MUC1-C→MYC pathway that activates genes encoding (i) glutathione-disulfide reductase (GSR), and (ii) the LDL receptor related protein 8 (LRP8), which inhibit ferroptosis by generating GSH and regulating selenium levels, respectively. GSR and LRP8 contribute to the function of glutathione peroxidase 4 (GPX4), an essential negative regulator of ferroptotic cell death. We demonstrate that targeting MUC1-C genetically or with the GO-203 peptide inhibitor suppresses GPX4 expression and GPX activity in association with the induction of ferroptosis. Studies of CSCs enriched by serial passage as tumorspheres further demonstrate that the effects of SAL are mediated by downregulation of MUC1-C and thereby overcoming resistance to ferroptosis. As confirmation of these results, rescue of MUC1-C downregulation with the MUC1-C cytoplasmic domain (i) reversed the suppression of GSR, LRP8 and GPX4 expression, and (ii) attenuated the induction of ferroptosis. These findings identify SAL as a unique small molecule inhibitor of MUC1-C signaling and demonstrate that MUC1-C is an important effector of resistance to ferroptosis.

MUC1-C integrates aerobic glycolysis with suppression of oxidative phosphorylation in triple-negative breast cancer stem cells

Activation of the MUC1-C protein promotes lineage plasticity, epigenetic reprogramming, and the cancer stem cell (CSC) state. The present studies performed on enriched populations of triple-negative breast cancer (TNBC) CSCs demonstrate that MUC1-C is essential for integrating activation of glycolytic pathway genes with self-renewal and tumorigenicity. MUC1-C further integrates the glycolytic pathway with suppression of mitochondrial DNA (mtDNA) genes encoding components of mitochondrial Complexes I-V. The repression of mtDNA genes is explained by MUC1-C-mediated (i) downregulation of the mitochondrial transcription factor A (TFAM) required for mtDNA transcription and (ii) induction of the mitochondrial transcription termination factor 3 (mTERF3). In support of pathogenesis that suppresses mitochondrial ROS production, targeting MUC1-C increases (i) mtDNA gene transcription, (ii) superoxide levels, and (iii) loss of self-renewal capacity. These findings and scRNA-seq analysis of CSC subpopulations indicate that MUC1-C regulates self-renewal and redox balance by integrating activation of glycolysis with suppression of oxidative phosphorylation.

MUC1-C intersects chronic inflammation with epigenetic reprogramming by regulating the set1a compass complex in cancer progression

Chronic inflammation promotes epigenetic reprogramming in cancer progression by pathways that remain unclear. The oncogenic MUC1-C protein is activated by the inflammatory NF-κB pathway in cancer cells. There is no known involvement of MUC1-C in regulation of the COMPASS family of H3K4 methyltransferases. We find that MUC1-C regulates (i) bulk H3K4 methylation levels, and (ii) the COMPASS SET1A/SETD1A and WDR5 genes by an NF-κB-mediated mechanism. The importance of MUC1-C in regulating the SET1A COMPASS complex is supported by the demonstration that MUC1-C and WDR5 drive expression of FOS, ATF3 and other AP-1 family members. In a feedforward loop, MUC1-C, WDR5 and AP-1 contribute to activation of genes encoding TRAF1, RELB and other effectors in the chronic NF-κB inflammatory response. We also show that MUC1-C, NF-κB, WDR5 and AP-1 are necessary for expression of the (i) KLF4 master regulator of the pluripotency network and (ii) NOTCH1 effector of stemness. In this way, MUC1-C/NF-κB complexes recruit SET1A/WDR5 and AP-1 to enhancer-like signatures in the KLF4 and NOTCH1 genes with increases in H3K4me3 levels, chromatin accessibility and transcription. These findings indicate that MUC1-C regulates the SET1A COMPASS complex and the induction of genes that integrate NF-κB-mediated chronic inflammation with cancer progression.

MUC1-C is necessary for SHP2 activation and BRAF inhibitor resistance in BRAF(V600E) mutant colorectal cancer

Colorectal cancers (CRCs) harboring the BRAF(V600E) mutation are associated with aggressive disease and resistance to BRAF inhibitors by feedback activation of the receptor tyrosine kinase (RTK)→RAS→MAPK pathway. The oncogenic MUC1-C protein promotes progression of colitis to CRC; whereas there is no known involvement of MUC1-C in BRAF(V600E) CRCs. The present work demonstrates that MUC1 expression is significantly upregulated in BRAF(V600E) vs wild-type CRCs. We show that BRAF(V600E) CRC cells are dependent on MUC1-C for proliferation and BRAF inhibitor (BRAFi) resistance. Mechanistically, MUC1-C integrates induction of MYC in driving cell cycle progression with activation of the SHP2 phosphotyrosine phosphatase, which enhances RTK-mediated RAS→ERK signaling. We demonstrate that targeting MUC1-C genetically and pharmacologically suppresses (i) activation of MYC, (ii) induction of the NOTCH1 stemness factor, and (iii) the capacity for self-renewal. We also show that MUC1-C associates with SHP2 and is required for SHP2 activation in driving BRAFi-induced feedback of ERK signaling. In this way, targeting MUC1-C in BRAFi-resistant BRAF(V600E) CRC tumors inhibits growth and sensitizes to BRAF inhibition. These findings demonstrate that MUC1-C is a target for the treatment of BRAF(V600E) CRCs and for reversing their resistance to BRAF inhibitors by suppressing the feedback MAPK pathway.

MUC1-C Dictates PBRM1-Mediated Chronic Induction of Interferon Signaling, DNA Damage Resistance, and Immunosuppression in Triple-Negative Breast Cancer

The polybromo-1 (PBRM1) chromatin-targeting subunit of the SWI/SNF PBAF chromatin remodeling complex drives DNA damage resistance and immune evasion in certain cancer cells through mechanisms that remain unclear. STAT1 and IRF1 are essential effectors of type I and II IFN pathways. Here, we report that MUC1-C is necessary for PBRM1 expression and that it forms a nuclear complex with PBRM1 in triple-negative breast cancer (TNBC) cells. Analysis of global transcriptional (RNA-seq) and chromatin accessibility (ATAC-seq) profiles further demonstrated that MUC1-C and PBRM1 drive STAT1 and IRF1 expression by increasing chromatin accessibility of promoter-like signatures (PLS) on their respective genes. We also found that MUC1-C, PBRM1, and IRF1 increase the expression and chromatin accessibility on PLSs of the (i) type II IFN pathway IDO1 and WARS genes and (ii) type I IFN pathway RIG-I, MDA5, and ISG15 genes that collectively contribute to DNA damage resistance and immune evasion. In support of these results, targeting MUC1-C in wild-type BRCA TNBC cells enhanced carboplatin-induced DNA damage and the loss of self-renewal capacity. In addition, MUC1-C was necessary for DNA damage resistance, self-renewal, and tumorigenicity in olaparib-resistant BRCA1-mutant TNBC cells. Analysis of TNBC tumors corroborated that (i) MUC1 and PBRM1 are associated with decreased responsiveness to chemotherapy and (ii) MUC1-C expression is associated with the depletion of tumor-infiltrating lymphocytes (TIL). These findings demonstrate that MUC1-C activates PBRM1, and thereby chromatin remodeling of IFN-stimulated genes that promote chronic inflammation, DNA damage resistance, and immune evasion.

IMPLICATIONS

MUC1-C is necessary for PBRM1-driven chromatin remodeling in chronic activation of IFN pathway genes that promote DNA damage resistance and immunosuppression.

MUC1-C is a master regulator of MICA/B NKG2D ligand and exosome secretion in human cancer cells

BACKGROUND

The MUC1-C protein evolved in mammals to protect barrier tissues from loss of homeostasis; however, MUC1-C promotes oncogenesis in association with chronic inflammation. Aberrant expression of MUC1-C in cancers has been linked to depletion and dysfunction of T cells in the tumor microenvironment. In contrast, there is no known involvement of MUC1-C in the regulation of natural killer (NK) cell function.

METHODS

Targeting MUC1-C genetically and pharmacologically in cancer cells was performed to assess effects on intracellular and cell surface expression of the MHC class I chain-related polypeptide A (MICA) and MICB ligands. The MICA/B promoters were analyzed for H3K27 and DNA methylation. Shedding of MICA/B was determined by ELISA. MUC1-C interactions with ERp5 and RAB27A were assessed by coimmunoprecipitation and direct binding studies. Exosomes were isolated for analysis of secretion. Purified NK cells were assayed for killing of cancer cell targets.

RESULTS

Our studies demonstrate that MUC1-C represses expression of the MICA and MICB ligands that activate the NK group 2D receptor. We show that the inflammatory MUC1-C→NF-κB pathway drives enhancer of zeste homolog 2-mediated and DNMT-mediated methylation of the MICA and MICB promoter regions. Targeting MUC1-C genetically and pharmacologically with the GO-203 inhibitor induced intracellular and cell surface MICA/B expression but not MICA/B cleavage. Mechanistically, MUC1-C regulates the ERp5 thiol oxidoreductase that is necessary for MICA/B protease digestion and shedding. In addition, MUC1-C interacts with the RAB27A protein, which is required for exosome formation and secretion. As a result, targeting MUC1-C markedly inhibited secretion of exosomes expressing MICA/B. In concert with these results, we show that targeting MUC1-C promotes NK cell-mediated killing.

CONCLUSIONS

These findings uncover pleotropic mechanisms by which MUC1-C confers evasion of cancer cells to NK cell recognition and destruction.

Dependence on the MUC1-C Oncoprotein in Classic, Variant, and Non-neuroendocrine Small Cell Lung Cancer

Small cell lung cancer (SCLC) is a recalcitrant malignancy defined by subtypes on the basis of differential expression of the ASCL1, NEUROD1, and POU2F3 transcription factors. The MUC1-C protein is activated in pulmonary epithelial cells by exposure to environmental carcinogens and promotes oncogenesis; however, there is no known association between MUC1-C and SCLC. We report that MUC1-C is expressed in classic neuroendocrine (NE) SCLC-A, variant NE SCLC-N and non-NE SCLC-P cells and activates the MYC pathway in these subtypes. In SCLC cells characterized by NE differentiation and DNA replication stress, we show that MUC1-C activates the MYC pathway in association with induction of E2F target genes and dysregulation of mitotic progression. Our studies further demonstrate that the MUC1-C→MYC pathway is necessary for induction of (i) NOTCH2, a marker of pulmonary NE stem cells that are the proposed cell of SCLC origin, and (ii) ASCL1 and NEUROD1. We also show that the MUC1-C→MYC→NOTCH2 network is necessary for self-renewal capacity and tumorigenicity of NE and non-NE SCLC cells. Analyses of datasets from SCLC tumors confirmed that MUC1 expression in single SCLC cells significantly associates with activation of the MYC pathway. These findings demonstrate that SCLC cells are addicted to MUC1-C and identify a potential new target for SCLC treatment.

IMPLICATIONS

This work uncovers addiction of SCLC cells to MUC1-C, which is a druggable target that could provide new opportunities for advancing SCLC treatment.

Recognition of pathogen-derived sphingolipids in Arabidopsis

In plants, many invading microbial pathogens are recognized by cell-surface pattern recognition receptors, which induce defense responses. Here, we show that the ceramide Phytophthora infestans-ceramide D (Pi-Cer D) from the plant pathogenic oomycete P. infestans triggers defense responses in Arabidopsis. Pi-Cer D is cleaved by an Arabidopsis apoplastic ceramidase, NEUTRAL CERAMIDASE 2 (NCER2), and the resulting 9-methyl-branched sphingoid base is recognized by a plasma membrane lectin receptor-like kinase, RESISTANT TO DFPM-INHIBITION OF ABSCISIC ACID SIGNALING 2 (RDA2). 9-Methyl-branched sphingoid base is specific to microbes and induces plant immune responses by physically interacting with RDA2. Loss of RDA2 or NCER2 function compromised Arabidopsis resistance against an oomycete pathogen. Thus, we elucidated the recognition mechanisms of pathogen-derived lipid molecules in plants.

Prominent response to platinum-based chemotherapy in a patient with BRCA2 mutant-neuroendocrine prostate cancer and MDM2 amplification

INTRODUCTION

Genomic profiling provides useful information for diagnosis, treatment, and prognosis, and detection of certain defects, such as DNA repair gene aberrations or microsatellite instability, can possibly lead to optimal treatment, but this testing has not been widely used to inform prostate cancer treatment.

CASE PRESENTATION

A 55-year-old man sequentially treated for prostate cancer was diagnosed as neuroendocrine prostate cancer from prostate specimens resected because of urinary retention. Subsequently, he received five cycles of platinum-based chemotherapy in total and responded well. We also performed next-generation sequencing of a sample from the prostate specimen and identified a breast cancer susceptibility gene mutation with Murine Double Minute 2 amplification and loss of heterozygosity in retinoblastoma 1.

CONCLUSION

We report a neuroendocrine prostate cancer patient with Murine Double Minute 2 amplification who experienced an aggressive course and for whom platinum-based chemotherapy was effective, and one of the reasons for the good response might be the breast cancer susceptibility gene mutation.

Splenic cord capillary hemangioma with non-islet cell tumor hypoglycemia: a case report

Background

Splenic cord capillary hemangioma is a rare benign vascular lesion classified as a splenic hamartoma. On the other hand, non-islet cell tumor hypoglycemia (NICTH) is one of the rare causes of spontaneous hypoglycemia and is considered to be one of the paraneoplastic syndromes. To the best of our knowledge, this is the first reported case of a splenic cord capillary hemangioma with NICTH.

Case presentation

A 25-year-old male was referred to our hospital with hypoglycemia. Except for his low blood sugar, there were no abnormal findings from laboratory tests, which included an endocrinological examination. Enhanced computed tomography confirmed the presence of a solid mass measuring about 6 cm in the retroperitoneum, and a tumorectomy was performed. During this operation, it became clear that the tumor turned out to be a splenic parenchyma, and as a result, a total splenectomy was performed. Microscopically, we diagnosed this as a cord capillary hemangioma, and through immunohistochemistry, we found that some tumor cells were positive for insulin-like growth factor -II. Fortunately, the hypoglycemia-related symptoms disappeared after surgical resection was performed. The patient is still alive and well without evidence of local tumor recurrence 15 years after the operation.

Conclusions

Splenic cord capillary hemangioma, one of the types of splenic hamartomas, is a very rare benign vascular lesion and might be associated with hypoglycemia thought to be NICTH.

Prognostic significance of erythrocyte protein band 4.1-like5 expression in upper urinary tract urothelial carcinoma

OBJECTIVES

The erythrocyte protein band 4.1-like5 (EPB4.1L5) regulates E-cadherin in cancer invasion and metastasis inducing epithelial-to-mesenchymal transition. This study aimed to investigate the biological significance of EPB4.1L5 in upper urinary tract urothelial carcinoma (UTUC).

METHODS

Retrospective analysis of the clinical records of 165 patients with UTUC (Ta-4N0M0) subjected to radical nephroureterectomy and immunohistochemical examination of EPB4.1L5 expression in those tissues.

RESULTS

The median follow-up period was 62.2 months (interquartile range = 77.0). The score of EPB4.1L5 significantly correlated with tumor grade, pathological T stage, and lymphovascular invasion (all P<0.001). The 5-year Kaplan-Meier recurrence-free survival and cancer-specific survival rates were 54.1% and 59.5% in patients with high EPB4.1L5 expression, compared with 81.6% and 87.2%, (all P<0.001) in their counterparts. Multivariate analyses revealed that high expression of EPB4.1L5 was one of the independent prognostic factors for tumor recurrence (P = 0.022, HR = 2.40) and cancer-specific survival (P = 0.015, HR = 2.94).

CONCLUSION

High EPB4.1L5 expression was related to worse clinical outcome in patients with UTUC. These results indicated that EPB4.1L5 could provide prognostic information in patients with UTUC regarding epithelial-to-mesenchymal transition.

A metastatic castration resistant prostate cancer patient with multiple bone metastases has durable biochemical and radiological response to docetaxel chemotherapy

Docetaxel chemotherapy for metastatic castration resistant prostate cancer patients has been thought palliative because the radiological response rate is low and durable response is rare. The patient was a 64-year-old man who was diagnosed with cT3aN0M0 prostate cancer and underwent external beam radiation therapy as the initial treatment. He underwent androgen deprivation therapy and 8 cycles of docetaxel chemotherapy. His PSA level decreased and became undetectable and the disease was confirmed to be stable by radiological examination. We report a rare case that a metastatic castration resistant prostate cancer patient with multiple bone metastases has durable radiological and biochemical response.

Influence of ABCB1 and ABCG2 polymorphisms on the antiemetic efficacy in patients with cancer receiving cisplatin-based chemotherapy: a TRIPLE pharmacogenomics study

Resistance to antiemetic treatment with 5-hydroxytryptamine-3 receptor antagonist is an issue. This study evaluated the potential roles of ABCB1 and ABCG2 polymorphisms in antiemetic treatment resistance in patients with cancer previously enrolled in a randomized controlled trial. A total of 156 patients were evaluated for their responses to antiemetic therapy and then subdivided into granisetron or palonosetron groups. The genotypes were evaluated for their association with antiemetic efficacy in each treatment groups. Additional risk factors associated with complete response (CR) were examined using a multivariate regression analysis. No significant associations were identified for genetic polymorphisms in the palonosetron group. In the granisetron group, patients with ABCB1 2677TT and 3435TT genotypes had higher proportion of CR. In addition to ABCB1 polymorphisms, gender and cisplatin dose were associated with granisetron response by univariate analysis. Multivariate logistic regression analysis revealed that the ABCB1 3435C>T polymorphism and cisplatin dose were significant predictors of CR.

Particle therapy using carbon ions or protons as a definitive therapy for patients with primary sacral chordoma

OBJECTIVE

This study retrospectively evaluated the efficacy and toxicity of particle therapy using carbon ions or protons for primary sacral chordomas.

METHODS

We evaluated 23 patients with primary sacral chordoma treated with carbon ion therapy (CIT) or proton therapy (PT) between July 2005 and June 2011 at the Hyogo Ion Beam Medical Center, Hyogo, Japan. The median patient age was 72 years. 14 patients were treated with 70.4 Gy equivalents (GyE) in 16 fractions and 9 were treated with 70.4 GyE in 32 fractions. CIT was used for 16 patients, and PT was used for 7 patients.

RESULTS

The median follow-up period was 38 months. At 3 years, local control (LC), overall survival (OS) and progression-free survival (PFS) for all patients were 94%, 83% and 68%, respectively. The log-rank test revealed that male sex was significantly related to better PFS (p=0.029). No other factors, including dose fractionation and ion type, were significant for LC, OS or PFS. In nine patients, ≥ Grade 3 acute dermatitis was observed, and ≥ Grade 3 late toxicities were observed in nine patients. The 32-fraction protocol reduced severe toxicities in both the acute and late phases compared with the 16-fraction protocol.

CONCLUSION

Particle therapy for patients with sacral chordoma showed favourable LC and OS. Severe toxicities were successfully reduced by modifying the dose fractionation and treatment planning in the later treatment era. Thus, this therapeutic modality should be considered useful and safe.

ADVANCES IN KNOWLEDGE

This is the first study including both CIT and PT for sacral chordomas.

Posterior maximization and averaging for Bayesian working model choice in the continual reassessment method

The continual reassessment method (CRM) is a method for estimating the maximum tolerated dose in a dose-finding study. Traditionally, use is made of a single working model or 'skeleton' idealizing an underlying true dose-toxicity relationship. This working model is chosen either by discussion with investigators or published data, before the beginning of the trial or simply on the basis of operating characteristics. To overcome the arbitrariness of the choice of such a single working model, Yin and Yuan (biJ. Am. Statist. Assoc. 2009; 104:954-968) propose a model averaging over a set of working models. Here, instead of averaging, we investigate some alternative Bayesian model criteria that maximize the posterior distribution. We propose three adaptive model-selecting CRMs using the Bayesian model selection criteria, in which we specify in advance a collection of candidate working models for the dose-toxicity relationship, especially initial guesses of toxicity probabilities, and adaptively select the only one working model among the candidates updated by using the original CRM for each working model, based on the posterior model probability, the posterior predictive loss or the deviance information criteria, during the course of the trial. These approaches were compared via a simulation study with the model averaging approach.

Transgenic analysis of the BmBLOS2 gene that governs the translucency of the larval integument of the silkworm, Bombyx mori

The larval integument of the silkworm, Bombyx mori, is opaque because urate granules accumulate in the epidermis. Although the biosynthetic pathway of uric acid is well studied, little is known about how uric acid accumulates as urate granules in epidermal cells. In the distinct oily (od) mutant silkworm, the larval integument is translucent because of the inability to construct urate granules. Recently, we have found that the od mutant has a genomic deletion in the B. mori homologue of the human biogenesis of lysosome-related organelles complex1, subunit 2 (BLOS2) gene (BmBLOS2). Here, we performed a molecular and functional characterization of BmBLOS2. Northern blot analysis showed that BmBLOS2 was ubiquitously expressed in various tissues. We analysed the structure of a newly isolated mutant (od(B) ) allelic to od and found a premature stop codon in the coding sequence of BmBLOS2 in this new mutation. Moreover, the translucent phenotype was rescued by the germ-line transformation of the wild-type BmBLOS2 allele into the od mutant. Our results suggest that BmBLOS2 is responsible for the od mutant phenotype and plays a crucial role in biogenesis of urate granules in the larval epidermis of the silkworm. The relationships amongst Hermansky-Pudlak syndrome (HPS) genes in mammals, granule group genes in Drosophila and translucent mutant genes in B. mori are discussed.

Genetic polymorphisms in folate pathway enzymes as a possible marker for predicting the outcome of methotrexate therapy in Japanese patients with rheumatoid arthritis

BACKGROUND

Low-dose methotrexate (MTX) therapy is widely used in the treatment of rheumatoid arthritis (RA). Though the difference in response to MTX between patients with RA is large, the factors that contribute to this variability remain unclear.

OBJECTIVE

We aimed to identify those factors with a particular emphasis on the pharmacogenetics of MTX.

METHOD

We evaluated the association of possible factors, including genetic polymorphisms of folate metabolic pathway enzymes, with the cumulative value of C-reactive protein, an index of MTX anti-inflammatory efficacy, in 87 Japanese patients with RA.

RESULTS

Polymorphisms of the reduced folate carrier gene (RFC) G80A and of the gamma-glutamylhydrolase gene (GGH) C-401T were more closely associated (beta = 2.1194, P = 0.0017) than other polymorphisms, with the anti-inflammatory response to MTX.

CONCLUSION

Patients with RA having RFC 80A and GGH-401T alleles were less responsive to MTX than those with RFC 80A and without GGH-401T alleles. Thus, this data may be useful for guiding treatment of RA patients with MTX.

Reproducibility of temporal volume change in CT of lung cancer: comparison of computer software and manual assessment

The purpose of this study was to investigate the reproducibility of volumetric software evaluation and manual evaluation of tumour growth. Three observers manually evaluated whether tumour volume was increasing, if it was unchanged, or if it had decreased in size in 2 serial CT examinations of 45 solid lung cancers. The tumour volumes were calculated 3 times using volumetric software and were evaluated using the same classifications as for manual evaluation. Both data sets were divided into three groups: growth or reduction with consistency among all three evaluations (group A), growth or reduction with consistency between only two evaluations (group B), and others (group C). The volume variation and relative volume variation were calculated from the median volumes measured by volumetric software. Although all 45 tumours were categorised in group A by volumetric software, only 21 tumours were categorised in group A by manual assessment. The relative volume variation of the manual assessment was 88.5 +/- 76.5%, 20.8 +/- 28.3% and 12.9 +/- 12.8% in group A, B and C, respectively. Significant differences were found between groups A and B (p<0.01) and between groups A and C (p<0.001). Inconsistency is often seen in manual assessment; in contrast, evaluation using volumetric software has good reproducibility, even when the relative change in tumour volume is small.

Identifying patients with peripheral-type early non-small cell lung cancer (T1N0M0) for whom irradiation of the primary focus alone could lead to successful treatment

We investigated the indication of radiotherapy in operable patients with peripheral-type early non-small cell lung cancer (T1N0M0 (TNM staging in 1997)). The subjects comprised 396 patients with non-small cell lung cancer in whom the clinical stage was evaluated as IA. We examined age, gender, Brinkmann's index, histopathological type, the grade of histopathological differentiation, tumour diameter and the level of carcinoembryonic antigen as factors involved in lymph node metastasis. Lymph node metastasis was detected in 79 patients (20%). Factors such as the grade of histopathological differentiation and tumour diameter were involved in lymph node metastasis. In well-differentiated lesions, the probability of metastasis was <10% even when the tumour diameter exceeded 2 cm. However, the probability rapidly increased with tumour size in moderately and poorly differentiated lesions. Among the patients with peripheral-type early non-small cell lung cancer (T1N0M0), the risk of lymph node metastasis was low in those with well-differentiated carcinoma and those with moderately differentiated lesions measuring </=1.5 cm in diameter. The proportion of our patients fitting these criteria was approximately 30%. For these patients, stereotactic body radiotherapy and particle therapy may be indicated.

Intra-arterial chemoradiotherapy for locally advanced oral cavity cancer: analysis of therapeutic results in 134 cases

The objective of this study was to investigate the therapeutic results of arterial injection therapy via the superficial temporal artery for 134 cases of stages III and IV (M0) oral cavity cancer retrospectively, and to clarify the prognostic factors. We administered intra-arterial chemoradiotherapy by continuous infusion of carboplatin in 65 cases from January 1993 to July 2002. Systemic chemotherapy was performed on 26 cases at the same time. We administered intra-arterial chemoradiotherapy by cisplatin with sodium thiosulphate in 69 cases from October 2002 to December 2006. Systemic chemotherapy was performed on 48 cases at the same time. The 3-year local control rate was 68.6% (T2-3: 77.9%; T4: 51.3%), and the 3-year survival rate was 53.9% (stage III: 62.9%; stage IV: 45.3%). Regarding the results of multivariate analysis of survival rates, age (<65), selective intra-arterial infusion, and the use of cisplatin as an agent for intra-arterial infusion were significant factors. The therapeutic results of intra-arterial chemoradiotherapy via the superficial temporal artery were not inferior to the results of surgery. In particular, the results of arterial injection therapy by cisplatin with sodium thiosulphate were excellent, so we believe that it will be a new therapy for advanced oral cavity cancer.

A phase I study of amrubicin (AMR) and irinotecan (CPT-11) in relapsed small cell lung cancer

18181

Background: AMR and CPT-11 have shown excellent activity in extensive small cell lung cancer (SCLC). The aim of this study was to determine the maximum tolerated dose (MTD) of amrubicin in combination with a fixed dose of CPT-11. Methods: Eligibility criteria were patients having pathologically proven SCLC, had relapsed after one or two previous chemotherapies, ECOG performance status (PS) of 0–2 and adequate organ function. Irinotecan was delivered as 50 mg/m2 on days 1 and 8, every 21 days. AMR was delivered on day 1. Doses of AMR were level 1: 80mg/ m2, level 2: 90 mg/m2 and level 3: 100 mg/ m2. Dose elevation was determined using continuous reassessment method (CRM). Tolerability was assessed after the 1st cycle. Another two cycles were conducted when disease progression or unacceptable toxicities were not observed. Results: Between June 2004 and October 2006, 18 patients were enrolled with the following characteristics: male/female, 15/3; median age, 66.3 years (range 57–61); PS 0/1/2: 4/14/0. Median number of previous treatment cycles was 5. A total of 40 courses were conducted. Grade 3/4 hematological toxicities of 1st cycle were: leukocytopenia: 67% (G3/4: 8/4); neutropenia: 89% (G3/4: 6/10), thrombocytopenia: 11% (G3/4: 1/1). Grade 3 febrile neutropenia occurred in 1 patient. Other grade 3 or greater non-hematological toxicities were observed in 4 of 40 courses (grade 3 infection in 3 courses and diarrhea in 1). In the first course, DLT was observed in 2 of 6 patients at dose level 2 (prolonged grade 4 neutropenia, febrile neutropenia), in 1 of 6 at dose level 3 (prolonged grade 4 neutropenia), MTD of amrubicin were determined by CRM to be 100 mg/m2 (level 3). Objective response was obtained in 4 patients (28%). Conclusions: This combination was well tolerated and showed activities in SCLC, though hematological toxicities were rather severe. Phase II trials are being planned in chemo naïve SCLC.

No significant financial relationships to disclose.

Functional characterization of chitinase from Cydia pomonella granulovirus

Baculovirus chitinases (V-CHIAs) play a crucial role in the terminal liquefaction of virus-infected larvae after death. Although v-chiAs from nucleopolyhedroviruses (NPVs) have been well characterized, little is known about v-chiAs from granuloviruses (GVs). We characterized the v-chiA of Cydia pomonella GV (CpGV) by constructing a recombinant Bombyx mori NPV (BmNPV) in which BmNPV v-chiA was replaced by CpGV v-chiA (103CpGV virus). CpGV v-chiA encoded an approximately 70-kDa chitinase with an exo-type substrate preference. CpGV V-CHIA lacked a C-terminal KDEL endoplasmic reticulum retention motif and was suggested to be a secretory protein. Terminal host liquefaction of B. mori larvae and proper folding of BmNPV-encoded cysteine protease (BmNPV V-CATH) were observed following infection with 103CpGV, indicating that CpGV v-chiA is able to compensate for the absence of its BmNPV counterpart. Our data suggest that the molecular interaction between V-CHIA and V-CATH may be conserved across a broad range of lepidopteran GVs and NPVs.

Relationship between the growth pattern of nasopharyngeal cancer and the cervical lymph nodes based on MRI findings: can the cervical radiation field be reduced in patients with nasopharyngeal cancer?

To identify patients with nasopharyngeal cancer in whom the cervical radiation field can be reduced, we classified the growth patterns of nasopharyngeal cancer based on MRI findings into 4 types and performed an evaluation. Based on MRI findings, we classified the growth patterns of primary cancer in 94 patients with nasopharyngeal cancer into Type 1 (superficial type), Type 2 (lateral invasive type), Type 3 (upward invasive type), and Type 4 (anterior extension type), and further classified Type 2, based upon nasopharyngoscopic findings, into Type 2a (unilateral invasive type) and Type 2b (bilateral invasive type). The cervical lymph node metastasis areas were evaluated according to these types. Type 2 showed a significantly higher incidence of cervical lymph node metastasis only on the ipsilateral side than the other types (p = 0.0024). In particular, all patients with Type 2a had cervical lymph node metastasis only on the ipsilateral side (p = 0.0212). This study suggests that the distribution of metastasised cervical lymph nodes depends on the pattern of tumour extent of the primary site.

The use of electrolyzed solutions for the cleaning and disinfecting of dialyzers

Recently, the use of electrolyzed solutions has attracted considerable interest in Japan. This study investigates the efficiency of electrolyzed solutions as disinfecting agents (DA) in the reuse of dialyzers and compares their efficiency to that of other disinfectants currently in use. The following 3 methods were employed. First, the rinsing time and rebound release of reused dialyzers were measured and compared after electrolyzed solutions, electrolyzed strong acid aqueous solution (ESAAS) and electrolyzed strong basic aqueous solution (ESBAS), made from reverse osmosis (RO) water (ESAAS, ESBAS; Generating apparatuses: Super Oxseed alpha 1000, Amano Corporation, Yokohama, Japan), 2% Dialox-cj (Teijin Gambro Medical, Tokyo, Japan), and 3.8% formalin were used as DAs. This involved performing dialysis with 2 types of dialyzers: a cellulose acetate membrane (CAM) dialyzer and a polysulfone membrane (PSM) dialyzer. The dialyzers were cleaned and disinfected using the different DA and left for 48 h. Next, after performing dialysis the dialyzer membranes were cleaned with a saline solution (0.9% NaCl) and RO water and then cleaned with the various DA. These membranes were observed using a scanning electron microscope (SEM) to check for the presence of physical and biological contaminants. Finally, in vitro tests were performed to determine the level of dialyzer clearance when PSM dialyzers were reused after having been cleaned and disinfected with the electrolyzed solutions. The rinsing time results for both the CAM and PSM dialyzers showed the electrolyzed solutions (ESBAS and ESAAS) as being undetectable within 10 min. With regard to the rebound release, for both the CAM and PSM dialyzers, the electrolyzed solutions were undetectable at all checking times between 30 and 240 min. Observation by SEM showed that cleaning with both ESAAS and ESBAS left the fewest contaminants, and cleaning with 2% Dialox-cj left the highest level of contaminants in the CAM dialyzers. With regard to experiments concerning use in vitro, no major changes in the dialyzer clearance were noticed after 6 uses. In every experiment, the previous investigations showed the electrolyzed solutions to be superior to 3. 8% formalin and 2% Dialox-cj DA for the reuse of dialyzers.

Use of a Technovit 7200 VLC to facilitate integrated determination of aluminum by light and electron microscopy

Technovit 7200 VLC is an excellent embedding medium for both inorganic histochemistry by light microscopy and X-ray microanalysis by scanning and transmission electron microscopy. Liver samples from rats after intraperitoneal treatment with aluminum chloride were fixed in glutaraldehyde and embedded in the resin. Thick sections were easily cut on an ultramicrotome and stained with aluminon for aluminum (Al). An intense positive reaction with aluminon was observed in the Kupffer cells by light microscopy. The surface structures of the same resin block cut for light microscopy were observed under a scanning electron microscope fitted with an energy dispersive X-ray spectrometer. The Kupffer cells appeared white in the backscattered mode. Localization of Al in the Kupffer cells was confirmed by an X-ray distribution map in the scanning electron microscope. Subcellular localization of Al in the Kupffer cells was performed on the same semithin sections using a transmission electron microscope equipped with an energy dispersive X-ray spectrometer. Most Al was found in lysosomes of the Kupffer cells. The resin was stable in the electron beam and chlorine-free.

Immunohistochemical localization of thrombomodulin in the stratified epithelium of the rat is restricted to the keratinizing epidermis

The expression and function of thrombomodulin (TM), an endothelial cofactor protein for thrombin-mediated protein C activation, in the epithelium are not fully characterized. This report describes the distribution and localization of TM in the various types of epithelia in the rat by light and electron microscopic immunocytochemistry. TM showed a limited distribution and was expressed by the keratinizing stratified epithelia of the skin, tongue, and esophagus, but was not present on the non-keratinizing epithelia of the vagina, ureter, trachea, stomach, or gut. An identical pattern of TM expression was seen in mucocutaneous junctions, transitional zones from a non-keratinizing stratified epithelium to a keratinizing epithelium at the edge of the eyelid and in the anal canal. As the keratinization of the stratified epithelia proceeded, the staining intensity increased in the transitional zones. Within the keratinizing stratified epithelia, TM staining was limited to the keratinocytes of the spinous layer, the spinous cells. The subcellular localization of TM on the spinous cells was restricted to the plasma membrane facing the intercellular spaces. TM was not detectable on the desmosomes or the two membranes making up the junction, presumably the nexus. The functional significance of TM in keratinizing epithelia is discussed.

The effect of electrolyzed strong acid aqueous solution on hemodialysis equipment

We reported the high effectiveness of electrolyzed strong acid aqueous solution (ESAAS) in cleaning hemodialysis lines. Although ESAAS has a strong bactericidal action, one concern is its strong acidity. It has a pH of 2.3-2.7, more than 1,000 mV in oxidation-reduction potential (ORP), and 10-50 ppm of available chlorine. The possibility of metal corrosion, degradation of synthetic resins, chorine gas emission, or dissolving calcium carbonate (CaCO3) deposits due to ESAAS's acidity was tested using in vitro experiments. The bactericidal and antiviral effects of various ESAAS's were also tested. Metal corrosion and synthetic resin degradation, although they occurred, were not serious. There were no problems with chlorine gas emission and dissolving of CaCO3 deposits. Each type of ESAAS showed almost the same bactericidal and antiviral effect, but in some cases differences were observed.

The cleaning and disinfecting of hemodialysis equipment using electrolyzed strong acid aqueous solution

In general, sodium hypochlorite, formalin, and Dialox (Teijin Gambro Medical, Ltd., Tokyo, Japan [main ingredients: H2O2, CH3CHOOOH, CH3COOH, H2O]) are used to clean and disinfect hemodialysis pipelines. In this study, the suitability of electrolyzed strong acid aqueous solution (ESAAS), which has attracted considerable interest in Japan because of its strong disinfecting properties, was examined. The crossover method was used to investigate the effectiveness of ESAAS in disinfecting the dialysis pipelines in comparison to that of sodium hypochlorite (200 ppm) used alternately with 1% acetic acid. The number of bacteria and the concentration of endotoxin (Et) were measured over an approximately 3 year period, starting in September 1994. Until then, 200 ppm sodium hypochlorite had been used alternately with 1% acetic acid, and the contamination of the pipeline had been marked. However, after switching to the ESAAS disinfection method, the dialysis pipelines very rapidly became cleaner. Therefore, the decision to develop an automated ESAAS cleaning system for long-term use was made. During the development period, the original disinfectants (200 ppm sodium hypochlorite used alternately with 1% acetic acid) were used as a stopgap. After confirmation of its performance and safety, the automated ESAAS cleaning system was introduced. To find out whether the decrease in bacteria secondarily caused a decrease in the Et concentration or whether the ESAAS directly inactivated the Et, an in vitro experiment was carried out. Highly concentrated Et, which had been left in the reverse osmosis (RO) drainage pipeline, was used as a sample to investigate the effects of ESAAS on Et at various concentrations and temperatures and on the recovery test. The results showed that ESAAS directly inactivated Et. This paper reports the results of the crossover test. The results of parallel tests carried out over an approximately 4 year period have already been reported. No significant problems occurred in the dialysis. The automated ESAAS cleaning system that was developed proved to be more economical than the conventional disinfecting method.

Immunocytochemical localization of thrombomodulin in the aqueous humor passage of the rat eye

This report describes the distribution and localization of thrombomodulin (TM) in the rat eye by light and electron microscopic immunocytochemistry. In addition to the endothelium of the entire vasculature, TM was found on the non-vascular structures lining the cavities of the posterior and anterior chambers and the limbus. TM was localized on the basal, lateral, and apical plasma membranes of the inner and outer ciliary epithelium, and the posterior iris epithelium in which there was no polarized expression of TM. In the anterior chamber, TM was localized on the luminal surface of the corneal endothelium, but was negative on the anterior border layer of the iris, which is composed of a discontinuous layer of fibroblasts and collagen fibers. Thus, TM was present at sites of cell-to-cell contact. TM was also present on the endothelia of the trabecular meshwork and the Schlemm's canal in the limbus. TM was localized not only on the luminal plasma membrane, but also on the cytoplasmic giant vacuoles in the endothelial cells of the Schlemm's canal. These findings extend the importance of anticoagulant mechanisms to the systems of secretion, circulation, and drainage of the aqueous humor.

Granulation in amine-storage organelles of mouse megakaryocytes: X-ray microprobe analysis and radioautography

The mechanisms and the processes of the storage of bivalent cations, ATP and 5-hydroxytryptamine (5HT) in the precursors of the amine-storage organelles of megakaryocytes were studied at the electron microscopic level. Although the precursors of the amine-storage organelles in the megakaryocytes fixed with glutaraldehyde and osmium tetroxide were empty, the electron opaque granules were observed in these organelles of the freeze-substituted megakaryocytes cut onto ethylene glycol. X-ray microprobe analysis demonstrated that they contained P, Mg and Ca. Quantitative differences in bivalent cations in the granules were not observed between megakaryocytes and blood platelets. Electron opaque uranaffin-reaction products were observed in the precursors of the amine-storage organelles of the megakaryocytes after treatment with the uranaffin reaction for ATP. However, few chromaffin positive granules were observed in the precursors of the amine-storage organelles after the chromaffin reaction for monoamines. Radioautographic analysis demonstrated that blood platelets avidly took up 3H-5HT but megakaryocytes were not able to accumulate 3H-5HT in vivo. These results indicate that megakaryocytes do not yet acquire the well developed uptake system of 5HT in vivo, while they readily accumulate cations and ATP in the precursors of the amine-storage organelles.

Localization of copper to afferent terminals in rat locus ceruleus, in contrast to mitochondrial copper in cerebellum

We examined copper localization in the locus ceruleus and cerebellum of rat brain by Timm's sulfide-silver staining, as modified by Danscher. Dense silver particles revealing copper localization were observed in sections of the locus ceruleus and cerebellum after pre-treatment with trichloroacetic acid. In the locus ceruleus, copper appeared to be distributed to neuropil rather than glial or neuronal cell bodies, and at the ultrastructural level copper was mainly localized on synaptic membranes of afferent terminals in contact with somatic spines or dendrites of locus ceruleus neurons, whereas copper was distributed to mitochondria in the granular layers of cerebellum and fine, sparse silver particles were observed throughout ependymal cells and epithelial cells of blood vessels. The specific localization of copper to afferent terminals in the locus ceruleus was confirmed by X-ray microanalysis, which showed a significant level of copper, but not zinc, in synaptic membranes. These results suggest a distinct role of copper depending on its regional distribution. Copper or copper protein may be involved in neurotransmission in the locus ceruleus but in mitochondrial activity in the cerebellum.

Histochemical evidence for abnormal copper distribution in the central nervous system of LEC mutant rat

After sulfide-silver staining if tissue sections treated with trichloroacetic acid, silver particles indicating the copper distribution were observed in several regions of normal rat brain, including the nucleus arcuatus, nucleus tractus solitarii, nucleus habenulae medialis, locus ceruleus, and cerebellum. However, copper in these regions disappeared or was greatly decreased in LEC mutant rats. The are postrema showed no detectable level of copper in normal rat brain, but exhibited an extremely high level of copper in LEC rats, with or without the onset of jaundice. The results suggest an abnormal copper metabolism in the central nervous system of LEC rat.

Presence of laminin B chain-like protein in bovine and rat adrenal chromaffin granules

The presence of a glycoprotein laminin in bovine adrenal chromaffin granules was examined by SDS-PAGE followed by immunoblotting. The two chromaffin granule membrane fractions were obtained by linear sucrose gradient centrifugation followed by freezing and thawing and gel-filtration of the chromaffin granule-rich fraction, respectively. The purity of the granules in these fractions was examined by electron microscopy. These fractions contained laminin B chain-like immunoreactivity as a major immunoreactive component against anti-laminin. Laminin A chain-like immunoreactive protein was undetectable. The soluble fraction of the chromaffin granules contained no immunoreactive peptide. The presence of laminin-like immunoreactivity in the chromaffin granules was confirmed by immunocytochemical study. Laminin B chain-like immunoreactivity was also identified in the rat adrenal chromaffin granule fraction. Laminin A chain was hardly detected, as in the case of bovine adrenals. Structure of laminin in chromaffin granules in bovine and rat adrenals may be different from that of mouse Englebrethe-Holm-Swarm sarcoma laminin. The functional significance of laminin B chain-like protein in the granules is unknown at present.